A Trypanosoma-associated disease, or trypanosomiasis, is a general term for diseases that develop due to infection by the parasitic protozoan of the genus Trypanosoma of the phylum kinetoplastea of the superclass Mastigophora. Every year, many humans and animals such as farm animals are reported to have died from Trypanosoma-associated diseases. The damages caused by Trypanosoma parasites are tremendous and serious.
Several therapeutic agents for treating a Trypanosoma-associated disease have been developed so far. However, those therapeutic agents must be used in early treatment, and also have problems such as production of severe side effects and development of resistant trypanosomes. No vaccine for treating a Trypanosoma-associated disease has been developed so far, and no effective therapeutic agent or method has been established as well.
As treatment of a disease, there is known a state-of-the-art treatment which uses an oligonucleotide and works by silencing a gene that responds to the disease. Examples of such a therapeutic method include a treatment which uses RNA interference using dsRNA (Non-patent Literature 1).
However, it has been reported that against Trypanosoma cruzi, which is a pathogen of American trypanosomiasis (Chagas disease), RNA interference cannot be achieved since dsRNA is degraded in both epimastigotes which are parasitic in insect vectors and amastigotes which have a proliferative phase in mammalian cells (Non-patent Literature 2).